Bearing supported skate wheel



March 28, 1967 A. M. URIBE BEARING SUPPORTED SKATE WHEEL Filed March 8,1965 2 Sheets-Sheet 1 INVENTOR ANT 0/V/0 M. UR/BE ATTORNEY March 28,1967 A. M. URIBE 3,311,417

BEARING SUPPORTED SKATE WHEEL Filed March 8, 1965 2 Sheets-Sheet 2 6 k ee sr 35 Fl 5 INVENTOR ANTON/0 M. UR/BE ATTORNEY ttes 3,311,417 BEARINGSUPPSRTED SKATE WHEEL Antonio M. Uribe, 1131 E. Merced Ave., West ovina,Calif. 91772 Filed Mar. 8, 1965, Ser. No. 437,846 11 Claims. (Q1.3015.7)

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boards, wheel mounted apparatus and cabinets and any other wheeleddevice that requires the use of bearing mounted wheels.

Bearing wheels presently available for such purposes most generallyemploy an open bearing and race construction. This open construction isnot very desirable because it is easy for foreign matter to enter thebearings and races and cause damage. In some applications the bearingsmay be exposed to the introduction of mud, abrasives, water and the likeand when this occurs in an open bearing and race construction thecombination is easily ruined. It is furthermore diflicult to properlylubricate an open hearing and race assembly since the lubricant willsoon leak out, particularly when the bearing and races are exposed toheat.

The present invention makes available an economical, precision typewheel and bearing assembly in which all wearing surfaces of the bearingsand races are sealed yet they can be easily lubricated, thereby insuringlonger bearing life and providing a smoother running assembly. The newbearing and race combination is designed to permit the rotating freedomof the wheel with which it is associated, to be adjusted. For examplethe races may be adjusted to exert thrust against the hearings to such adegree that each bearing will remain axially fixed between the two racesnormal to the axis of the wheel and each bearing will in effect act as awheel on which the surface of the race that is parallel to the axis ofthe wheel can roll, in which case only thewheel will be free to turn.When the pressure against the bearings is relieved all elements of theassembly are free to turn and even the axle can turn inside itssupporting bearing when all elements of the combination are notrestricted. This arrangement of adjustable wheel bearings, races, andaxle elements provides a wheel and bearing assembly that, when aconstant driving force is applied to the rim of the wheel, can rotate atdifferent speeds depending on the degree of freedom of the variouselements.

One purpose of this invention is to provide a simple, precision type ofsealed bearing and wheel assembly that requires no expensive orintricate parts.

Another purpose of the invention is to provide a bearing and wheelcombination in which the rotation of the various races, axle, bearingsand wheel can be regulated by simply adjustin the position of anadjusting member, thereby making available a bearing and wheel assemblythat can be made to rotate at various angular speeds while 'a constantforce is applied to the rim of the wheel.

atent O Other purposes and advantages of this invention will becomeapparent from the following detailed description and accompanyingdrawings in which:

FIG. 1 is a longitudinal cross section view of a pair of ball bearingwheels and assemblies mounted on a supporting shaft journaled in thebearing of a truck support.

FIG. 2 is an end view of the wheels in FIG. 1 taken on the line 2-2 andshowing the axle in cross section.

FIG. 3 is a view of the wheel as it appears from the outside end.

FIG. 4 is a view of an alternative arrangement in which the end race andsleeve race are combined to form a. single unit.

FIG. 5 is a view of an alternative construction in which roller bearingswith hemispherical ends are used in place of ball bearings, thisconstruction being preferable when heavy loads are to be supported bythe bearing and wheel combination.

FIG. 6 is a view of an alternative construction in which the end racesare step formed to further insure freedom from foreign matter in thewheel bearings and races; at single sleeve race is also shown in placeof the two sleeve races of FIG. 1.

Referring to the drawings there is shown an axle 10 that is ofsuflicient diameter to permit it to snugly rotate in bearing 11 that isa part of support 12 of a so-called truck mounting (not shown). Support12 is shown broken a short distance from bearing 11 for conveniencesince the remainder of the truck of which the bearing is an element,does not constitute any part of this invention. Bearing 11 could be apart of any other support that will journal axle 19-.

A wheel or wheels, 13 is rotatably mounted on axle 10 by means of acombination of races and bearings that are associated with the wheel.The wheels are preferably constructed of a lightweight, wear resistantmaterial such as nylon, however, the wheel can be made of any otherdesired material such as metal, rubber, wood, other type of plasticmaterial, etc., depending on the particular use to which the wheel is tobe put. Wheels 13 of FIGS. 1, 2 and 3 are shown as having a cellulararrangement. This is done to lighten the wheel as much as possible andat the same time to minimize the amount of material required in formingthe wheel. It is intended that any other cellular arrangement can beused, and likewise the wheels could be made solid if preferred.

Each wheel 13 is provided with an axial bore 14 extending longitudinallythrough the wheel. An axial counterbore starting from the outside end ofthe wheel forms a first cavity 15 that is cylindrical and extendsaxially into the wheel a predetermined distance terminating in ashoulder 16 that is normal to the axis of bore 14. The opposite side ofwheel 13 is also provided wit-h an axial counterbore that forms acylindrical cavity 17 that continues axially into the wheel the requireddistance terminating in shoulder 18 that is also normal to the axis ofbore 14; shoulders 16 and 18 are in spaced relationship with each other.Flange 19 is formed between shoulders 16 and 18. The diameter ofcavities 15 and 17 is preferably the same.

A first cup-shaped race 21) is provided with an axial bore 21 that isthe same or larger in diameter than bore 14. Cup-shaped race 29 isshorter in length than the length of cavity 15. The outer diameter ofrace 20 is such that when inserted in cavity 15 until its bottom surface22 rests against shoulder 16, it will be securely held in wheel 13. Asecond cup-shaped race 24 has an axial bore 25 corresponding to bore 21and its length corresponds to the length of axial cavity 17. Cup-shapedrace 24 is inserted in cavity 17 until the outer surface 26 of bottom 27rests against shoulder 18, and it likewise is securely held in wheel 13.The annular flange portion of cup-shaped race that is circumferential,and the fiat disclike race 22 with its central bore 21 could be separateif so desired, in which case the inner rim of the circumferentialannular portion would be in contact with the fiat disclike annular race.In those cases where the Wheels are made of castable material, thewheels could be cast or molded around cup-shaped races 21) and 24.

FIG. 1 shows a first cylindrical end race 28 provided with an axial bore29 that has a diameter that will permit race 28 to rotate freely butsnugly on axle it). The outer diameter 30 of end race 28 is such that itwill permit race 28 to snugly slide into yet be free to revolve withinthe outer end portion of the inner horizontal circular surface 31 ofcup-shaped race Zti.

A second cylindrical end race 32 is provided with an axial bore 33 thatis large enough in diameter to permit race 32 to revolve freely butsnugly on axle Ill. The outer diameter of end race 32, designated as 34is proportioned to permit end race 32 to snugly slide into the outer endportion of horizontal circular surface 35 of cup-shaped race 24 andstill be free to revolve therein.

FIG. 1 shows a first sleeve race 3d having an axial bore 37 of adiameter sufiiciently to permit sleeve race 36 to revolve on axle 10snugly but freely; the outer cylindrical surface 4!) of sleeve race 36is made slightly smaller than the diameter of bore 21 of cup-shaped race20 and bore 14 of the wheel. In FIG. 1 race 36 has its outer end 38resting against inner surface 39* of cylindrical end race 23 and sleeverace 36 extends toward the center of wheel 13 a substantial distance.

A second sleeve race 41 has an axial bore 42 that is of such a diameteras to permit race 41 to rotate snugly but freely on axle It). The outercylindrical surface 43 of the sleeve race is made slightly smaller indiameter than bore 25 of cup-shaped race 24 and bore 14 of the wheel.This race also extends a substantial distance from inner surface d4 ofend race 32 toward the central portion of wheel 13 and toward the innerend of sleeve race 36 so that when the respective inner surface of theend races, the bearings and the inner surface of the bottom of therespective cup-shaped race are in contact with each other, the innerends of sleeve races 36 and 41 will just touch.

An alternative construction is shown in H6. 4 in which end race 28 and32 respectively could be made an integral part of sleeve races 36 and 41respectively.

A plurality of bearings such as the ball bearings shown in FIG. 1,designated as 46, are inserted in the annular cavity 47 that is formedby inner surface 39 of sleeve race 36, the inner horizontal surface 31of cup-shaped race 20, inner surface 48 of bottom portion 23 ofcupshaped race 20, and outer cylindrical surface of sleeve race 36.

A second plurality of ball bearings 49 are inserted in annular cavity 50that is formed by inner surface 44 of cylindrical end race 32, innerhorizontal surface 35 of cup-shaped race 24, inner surface 51 of bottomportion 27 of cup-shaped race 24 and outer cylindrical surface 43 ofsleeve race 41.

Axle 10 is preferably provided with a head portion 52 at one end and isprovided with a threaded portion 53 at the opposite end that extends fora suitable distance. Adjusting nut 54- is threaded on threaded portion53. If preferred both ends of axle 10 could be threaded and boththreaded portion would then be supplied with nuts such as 54.

FIG. 5 shows an alternate construction in which ball bearings 46 arereplaced by a plurality of roller bearings 56 having hemispherical ends57. In this embodiment the cavity 47 of FIG. 1 would have to be madesufficiently long to accommodate the added length of the roller bearingsand cup-shaped race it) as well as cavity 15 would have to be madelonger accordingly. The other side of the wheel, the cavity, race andbearings would have to be increased in the same manner. Thisconstruction is especially desirable when the wheels and axle will haveto support heavy loads. The added length of the bearing surface servesto distribute the weight over a greater length of contact surface. Ifdesired the end portion of the roller bearings could be made conicalwith the apex having a small radius to avoid using a sharp pointed endwhich would dig into the respective surface of the end race andcup-shaped race.

FIG. 6 illustrates an alternative construction in which end races as areprovided with a flange 61 that is slightly smaller in diameter than thediameter of the respective cavity 15 or 1'7. The inner surface d2 offlange 61 comes close to but does not touch the rims 63 or 64 of cupshaped races 28 and 24. The remainder of end race is the same as endraces 23 and 32. In this construction either a pair of sleeve races 36and 41, that are long enough to permit their inner ends to just touchwhen their outer ends are in contact with the inner surfaces of endraces 23 and 32 respectively and the bearings are in contact with thenormal flanges of their respective cup-shaped race and their respectiveend race, as shown in FIG. 1, may be used. Preferably a single sleeverace 65 that is long enough to correspond to the length of both sleeveraces 36 and 41 is used in place of the two sleeve races, the singlesleeve race construction being shown in FIGURES 5 and 6.

The manner in which the wheel and bearings are as semhled and operateare as follows:

Ball bearings 46 or roller bearings $6 are placed circumferentially incup-shaped race 26 and rest against surface 31 of cup-shaped race 2% Endrace 28 is slipped on axle it until it rests against head 52 of the axleand sleeve race 36 is also placed on the axle until it rests against endrace 28. The axle, end race and the sleeve race is inserted in the bore14 of the wheel and end race 28 is then inserted into the open end ofcup shaped race 2i) until it rests against bearings 46; the balls orroller hearings will also be resting against the outer cylindricalsurface 44 of sleeve race 36.

Second sleeve race 41 is introduced on axle 10 on the other side of thewheel and ball or roller bearings 49 or 56 are circumferentially piacedin the cavity formed on this side of the wheel and will normally restagainst 35 and 50 of cup-shaped race 24 as well as outer cylindricalsurface 55 of sleeve race 4-1. End race 32 is slipped on axle lit andthen axle it), is journaled in bearing 11. In the construction shown inFIG. 1 and in all other two wheel assemblies, a second wheel 13 ismounted on the projecting portion of axle it? that projects fromsupporting bearing 11 and substantially the reverse procedure isfollowed from the one used in mounting the first wheel.

After all of the bearings, races and wheels are mounted on supportingbearing 11, adjusting nut 54 is threaded on axle l0 and the nut istightened until it applies the required degree of pressure on end race32. Whenever the nut is not in a position to clamp the bearings betweentheir cup shaped race and the end race, each internal sleeve race, theend races, the bearings, and the wheels are all free to revolve aboutthe axle. Whenever the axle can turn it is also free to turn in bearing11. When nut 5- is positioned so that the bearings are clamped tightlybetween their respective cup-shaped race on one side and theirrespective end race on the other side, the sleeve race or races willalso be tightly clamped between their respective end races and the endraces in turn will be securely held by either the head of the axle orthe adjusting nut as well as the respective end of bearing 11 thusmaking it impossible for the axle or any of the sleeve or end races toturn. The horizontal surface of each cup-shaped race will roll on thebearings and thus only the wheels and hearings will turn.

The device shown in FIG. 6 operates in the same manner as the one shownin FIG. 1 with the exception that the inner surfaces 66 of flange 61will never come in contact with ths rims 63 or 64 of races 20 and 24even when the bearings are tightly held between the proper surface oftheir respective cup shaped race and the respective end race.

A feature of this construction is that each bearing can be in contactwith the surfaces of three races at one time.

Various alterations may be made in the details of construction withoutdeparting from the scope of the present invention as defined by thefollowing claims.

I claim:

1. A hearing supported wheel assembly comprising: a wheel, said wheelbeing provided with an axial bore extending therethrough; a first axialcounterbore extending into said wheel a predetermined distance from oneend thereof and forming a first axial cavity; a second axial counterboreextending into said wheel a predetermined distance from the opposite endof said wheel and forming a second axial cavity, the ends of said firstand second axial cavities forming shoulders that are in spacedrelationship to each other; an axle having an enlarged end portion atone end and an enlarged adjustable retaining means at the opposite endthereof, the axle extending through said wheel and having a diametersmaller than the diameter of the axial bore; a first and a secondannular disc race in contact with its corresponding shoulder of saidfirst and second cavities, each annular disc race having a central boreat least as large as the axial bore of said wheel; a first and a secondcircumferential annular race secured within its respective first andsecond axial cavity, each of said circumferential annular races being incontact with its respective annular disc race; an annular sleeve racesnugly rotatable on said axle, a portion of said sleeve race beingcoextensive with a portion of said first and second circumferentialannular races and having an external diameter that is smaller than theaxial bore of said wheel; a first and a second annular disclike endrace, each end race being snugly rotatable on said axle and having anoutside diameter to permit it to slide snugly into and snugly revolvewithin its respective annular circumferential race; and a plurality ofbearings disposed within each cavity formed between the correspondingannular circumferential race, annular disc race, the respective portionof the sleeve race and the inner surface of the end race, the degree ofthrust applied to the bearing being determined by the position of theadjustable retaining means at one end of said axle.

2. A bearing supported wheel assembly comprising: a wheel, said wheelbeing provided with an axial bore extending therethrough; a first axialcounterbore extending into said wheel a predetermined distance from oneend thereof and forming a first axial cavity; a second axial counterboreextending into said wheel a predetermined distance from the opposite endthereof and forming a second axial cavity, the ends of said first andsecond axial cavities forming shoulders that are in spaced relationshipto each other; an axle having an enlarged retaining means at one endthereof and provided with an enlarged adjustable retaining means at theopposite end thereof, the axle extending through said wheel and beingsmaller in diameter than said axial bore; bearing means for rotatablysupporting said axle; a first and a second annular disc race in contactwith its respective shoulder of said first and second cavities, eachannular disc race having a central bore at least as large as the axialbore of said wheel; a first and a second circumferential annular racesecured within its respective axial cavity, each of said first andsecond circumferential annular races being in contact with itscorresponding annular disc race; an annular sleeve race snugly rotatableon said axle, a portion of said sleeve race being coextensive with aportion of said first and second circumferential annular races andhaving an external diameter that is smaller than the axial bore of saidwheel; a first and a second annular end race, each of said end races 6being snugly rotatable on said axle and having an outside diameter thatwill permit it to snugly slide into and snugly rotate within itsrespective annular circumferential race, one of said end races adjoiningsaid enlarged retaining means at one end of the axle, the other end raceadjoining the corresponding end of said bearing means; and a pluralityof bearings disposed in each cavity formed between the respectiveannular circumferential race, the cooperating annular disc race, therespective portion of said sleeve race, and the inner surface of therespective end race, the degree of thrust applied to said bearings beingdetermined by the force exerted against said end races by the head ofsaid axle and the end of said bearing and controlled by the position ofthe adjustable retaining means at the opposite end of said axle.

3. A bearing supported wheel assembly comprising: a wheel, said wheelbeing provided with an axial bore extending therethrough and having afirst axial counterbore extending into said wheel a predetermineddistance from one end thereof and forming a first axial cavity; a secondaxial counterbore extending in to said wheel a predetermined distancefrom the opposite end thereof and forming a second axial cavity, theends of said first and second axial cavities forming shoulders that arein spaced relationship with each other; an axle having an enlargedretaining means at one end thereof and an enlarged adjustable retainingmeans at the other end thereof, the axle extending through said wheeland having a diameter smaller than the diameter of said axial bore; afirst and a second cup-shaped race, each cup-shaped race being providedwith an axial bore corresponding substantially with the diameter of theaxial bore of said wheel, said cup shaped races being secured withintheir respective cavity and resting against their respective shoulder;an annular sleeve race snugly rotatable on said axle, a portion of saidsleeve race being coextensive in length with a portion of said first andsecond cup-shaped races and having an outside diameter that is smallerthan the axial bore of said wheel; a first and a second annular disclikeend race, each end race being snugly rotatable on said axle and havingan outside diameter to permit it to slide snugly into and to snuglyrevolve within its respective cup-shaped race; and a plurality ofbearings disposed within each cavity formed between the inner surface ofthe respective end race, the inner circumferential surface of therespective cup-shaped race, the outer cylindrical surface of therespective portion of the sleeve race, and the inner surface of thebottom portion of the cup-shaped 'race, the thrust against the bearingsbeing determined by the position of the adjustable retaining means atone end of said axle.

4. A bearing supported wheel assembly according to claim 3 wherein saidbearings are ball bearings.

5. A bearing supported wheel assembly according to claim 3 wherein saidbearings are roller bearings.

6. A bearing supported wheel assembly according to claim 3 wherein saidend races are provided with an external flange that is larger indiameter than the internal circumferential surface of said cup-shapedrace, the inner surface of said flange on said end races being always inspaced relationship with the external end annulus of saidcircumferential portion of said cup-shaped race.

7. A bearing supported wheel assembly comprising: a wheel, said wheelbeing provided with an axial bore extending therethrough, and having afirst axial counterbore extending into said Wheel a predetermineddistance from one end thereof and forming a first axial cavity; a secondaxial counterbore extending into said wheel a predetermined distancefrom the opposite end thereof and forming a second axial cavity, theends of said first and second axial cavities forming shoulders that arein spaced relationship with each other; an axle having an enlargedretaining means at one end thereof and having an enlarged adjustableretaining means at the other end thereof, the axle extending throughsaid wheel and having a diameter smaller than the diameter of said wheelbore; a bearing means for rotatably supporting said axle, said bearingmeans being secured to supporting means; a first and a second cup-shapedrace, each cup-shaped race being provided with an axial borecorresponding substantially in diameter to the diameter of said axialbore of said wheel, said cup shaped races being secured within theirrespective axial cavity and resting against the corresponding shoulderof said cavity; an annular sleeve race snugly rotatable on said axle, aportion of said sleeve race being coextensive with a portion of saidfirst and second cup-shaped races and having an outside diameter that issmaller than the axial bore of said wheel; a first and a,second annulardisclike end race, each end race being snugly rotatable on said axle andhaving an outside diameter to permit it to slide snugly into and revolvewithin its respective cup-shaped race; and a plurality of bearingsdisposed Within each cavity formed between the inner surface of therespective end race, the inner circumferential surface of the respectivecup-shaped race, the respective outer cylindrical surface of the sleeverace, and the inner surface of the bottom portion of the respectivecup-shaped race, the thrust against the bearings being determined by theposition of the adjustable retaining means on the end of said axleextending beyond said bearing means.

8. A hearing supported wheel assembly comprising: a first and a secondwheel, each of said wheels being provided with an axial bore extendingthcrethrough and having a first axial counterbore extending into eachWheel a predetermined distance from one end thereof and forming a firstaxial cavity; a second axial counterbore extending into each of saidwheels a predetermined distance from the opposite end thereof andforming a second axial cavity, the ends of said first and second axialcavities forming shoulders that are in spaced relationship with eachother; an axle having an enlarged retaining means at one end thereof andhaving an enlarged re taining means that is adjustable in position atthe opposite end thereof, said axle extending through both of saidwheels and having a diameter that is smaller than the diameters of saidwheel bores; a bearing means for rotatably supporting said axleintermediate said first and second wheels; said bearing means beingsecured to a supporting means; each wheel being provided with a firstand a second cup-shaped race, each cup-shaped race having an axial borecorresponding substantially in diameter to the diameter of therespective axial bore of each wheel, said cup-shaped races being securedwithin the respective axial cavity of the respective Wheel and restingagainst the shoulder of the respective cavity; each wheel being providedwith an annular sleeve race that is snugly rtatable on said axle, aportion of said sleeve races being coextensive with a portion of saidfirst and second cupshaped races of each wheel and having an outsidediameter that is smaller than the axial bore of the respective wheel; afirst and a second disclike end race in each wheel, each end race beingsnugly rotatable on said axle and having an outside diameter that willpermit it to slide snugly into and revolve within its respective cupshaped race; and a plurality of bearings disposed within each of thefour cavities formed between the inner surface of the respective endrace, the inner circumferential surface of the respective cup-shapedrace, the respective outer cylindrical surface of the respective portionof each sleeve race, and the respective inner surface of the bottomportion of the corresponding cup-shaped race, thrust against thehearings in each wheel being determined by the degree of contact betweenthe head retaining end portion of the axle against the first end race ofthe first wheel, the degree of contact between the second end race ofthe first wheel with the corresponding end of said supporting bearing,the degree of contact between the second end race of the second wheelwith the corresponding end of the supporting bearing, and the degree ofcontact between the first end race of said second wheel and theadjustable enlarged retaining means at the opposite end of said axle.

9. A hearing supported wheel assembly comprising: a wheel, said wheelbeing provided with an axial bore extending therethrough and having afirst axial counterbore extending into said wheel a predetermineddistance from one end thereof and forming a first axial cavity; a secondaxial counterbore extending into said wheel a predetermined distancefrom the opposite end thereof and forming a second axial cavity, theends of said first and second axial cavities forming shoulders that arein spaced relationship with each other; an axle having an enlargedretaining means at one end thereof and an enlarged adjustable retainingmeans at the other end thereof, the axle extending through said wheeland having a diameter smaller than the diameter of said axial bore; afirst and a second cup-shaped race, each cup-shaped race being providedwith an axial bore corresponding substantially with the diameter of theaxial bore of said wheel, said cup-shaped races being secured withintheir respective cavity and resting against their respective shoulder; afirst and a second annular disclike end race, each end race being snuglyrotatable on said axle and having an outside diameter that will permitthe end race to slide snugly into and snugly revolve within itsrespective cup-shaped race; a first and a second annular sleeve racethat are snugly rotatable on said axle, the outside diameter of eachsleeve race being smaller than the axial bore of said wheel, a portionof the combined lengths of said first and second sleeve races beingcoextensive with a portion of said first and second cup-shaped races,the inner ends of said sleeve races being just in contact with eachother when bearings are clamped between the bottoms of said cup-shapdraces and the inner surface of the respective end race; and a pluralityof bearings disposed within each cavity formed between the inner surfaceof the respective end race, the inner circumferential surface of therespective cup-shaped race, the inner surface of the bottom portion ofthe cup-shaped race, and the outer cylindrical surface of the respectiveannular sleeve race, the thrust against the bearings being determined bythe position of the adjustable retaining means at one end of said axle.

10. A bearing supported wheel assembly according to claim 9, whereinsaid first and second end races are secured to the external end of saidfirst and second sleeve races respectively.

References (Iited by the Examiner UNITED STATES PATENTS 343,185 6/1886Mendenhall 30l5.7 2,649,337 8/1953 Ware 301-5.7 2,734,777 2/1956 JeWett30l5.7

FOREIGN PATENTS 497,937 10/1919 France.

BENJAMIN HERSH, Primary Examiner.

RICHARD J. JOHNSON, Examiner.

1. A BEARING SUPPORTED WHEEL ASSEMBLY COMPRISING: A WHEEL, SAID WHEELBEING PROVIDED WITH AN AXIAL BORE EXTENDING THERETHROUGH; A FIRST AXIALCOUNTERBORE EXTENDING INTO SAID WHEEL A PREDETERMINED DISTANCE FROM ONEEND THEREOF AND FORMING A FIRST AXIAL CAVITY; A SECOND AXIAL COUNTERBOREEXTENDING INTO SAID WHEEL A PREDETERMINED DISTANCE FROM THE OPPOSITE ENDOF SAID WHEEL AND FORMING A SECOND AXIAL CAVITY, THE ENDS OF SAID FIRSTAND SECOND AXIAL CAVITIES FORMING SHOULDERS THAT ARE IN SPACEDRELATIONSHIP TO EACH OTHER; AN AXLE HAVING AN ENLARGED END PORTION ATONE END AND AN ENLARGED ADJUSTABLE RETAINING MEANS AT THE OPPOSITE ENDTHEREOF, THE AXLE EXTENDING THROUGH SAID WHEEL AND HAVING A DIAMETERSMALLER THAN THE DIAMETER OF THE AXIAL BORE; A FIRST AND A SECONDANNULAR DISC RACE IN CONTACT WITH ITS CORRESPONDING SHOULDER OF SAIDFIRST AND SECOND CAVITIES, EACH ANNULAR DISC RACE HAVING A CENTRAL BOREAT LEAST AS LARGE AS THE AXIAL BORE OF SAID WHEEL; A FIRST AND A SECONDCIRCUMFERENTIAL ANNULAR RACE SECURED WITHIN ITS RESPECTIVE FIRST ANDSECOND AXIAL CAVITY, EACH OF SAID CIRCUMFERENTIAL ANNULAR RACES BEING INCONTACT WITH ITS RESPECTIVE ANNULAR DISC RACES; AN ANNULAR SLEEVE RACESNUGLY ROTATABLE ON SAID AXLE, A PORTION OF SAID SLEEVE RACE BEINGCOEXTENSIVE WITH A PORTION OF SAID FIRST AND SECOND CIRCUMFERENTIALANNULAR RACES AND HAVING AN EXTERNAL DIAMETER THAT IS SMALLER THAN THEAXIAL BORE OF SAID WHEEL; A FIRST AND A SECOND ANNULAR DISCLIKE ENDRACE, EACH END RACE BEING SNUGLY ROTATABLE ON SAID AXLE AND HAVING ANOUTSIDE DIAMETER TO PERMIT IT TO SLIDE SNUGLY INTO AND SNUGLY REVOLVEWITHIN ITS RESPECTIVE ANNULAR CIRCUMFERENTIAL RACE; AND A PLURALITY OFBEARINGS DISPOSED WITHIN EACH CAVITY FORMED BETWEEN THE CORRESPONDINGANNULAR CIRCUMFERENTIAL RACE, ANNULAR DISC RACE, THE RESPECTIVE PORTIONOF THE SLEEVE RACE AND THE INNER SURFACE OF THE END RACE, THE DEGREE OFTHRUST APPLIED TO THE BEARING BEING DETERMINED BY THE POSITION OF THEADJUSTABLE RETAINING MEANS AT ONE END OF SAID AXLE.